Finding the Fourth Proportional to 100.76, 138.98 and 69.72

Step by Step Solution

1. Step 1: Write the proportion equation
   100.76 : 138.98 = 69.72 : x
2. Step 2: Convert to fraction form
   100.76/138.98 = 69.72/x
3. Step 3: Cross multiply
   100.76x = 138.98 × 69.72
4. Step 4: Simplify right side
   100.76x = 9,689.69
5. Step 5: Solve for x
   x = 9,689.69/100.76
6. Step 6: Final answer
   x = 96.17